In combined heat and power (CHP) plants, apart from producing power from fuels, useful heat is coupled out for heating purposes. CHP plants provide heat for heating public and private buildings. Depending on their sizes, CHP plants are in particular adequate for being used in single-family homes, residential buildings and business enterprises. Since apart from power production, CHP plants also emit heat for heating purposes, they reach higher degrees of utilization compared to steam power stations that are merely used for power production.
The heating power required by a building far sufficient heating highly depends on outside temperatures. To ensure that the building is sufficiently supplied with thermal heat even in cold weather, the CHP plant is designed for the so-called standard design temperature which is relatively low and only rarely reached at all over the year. Ta be able to use a CHP plant for heating buildings to an economically reasonable degree, it is in practice typically only designed for a fraction of the maximum heating power required according to the standard design temperature, and when the maximum heating power is actually required, it is provided by a peak load boiler. This, however, complicates the construction of the heating installation, and higher investment costs are incurred due to the need for the peak load boiler. Thus, an object underlying the present invention is to provide a CHP plant in which a sufficiently high increase in heating power, compared to normal operation, is permitted for reliably heating buildings at low outside temperatures without any need for a peak load boiler.